Multi-electrode molecular sensing devices and methods of making the same
A molecular sensor includes a substrate defining a substrate plane, and a plurality of pairs of electrode sheets above or below the substrate at an angle to the substrate plane. The molecular sensor further includes a plurality of inner dielectric sheets between each electrode sheet in each pair of electrode sheets of the plurality of pairs, and an outer dielectric sheet between each pair of electrode sheets of the plurality of pairs.
1. A method of manufacturing a structure usable in a molecular sensor device, the method comprising:
providing a substrate that defines a substrate plane and further comprises a protrusion protruding from the substrate at an angle to the substrate plane;
depositing a first electrode layer on the substrate to form a first electrode sheet;
depositing an inner dielectric layer on the first electrode sheet to form an inner dielectric sheet;
depositing a second electrode layer on the inner dielectric sheet to form a second electrode sheet;
depositing an outer dielectric layer on the second electrode sheet to form an outer dielectric sheet,
planarizing the first and second electrode sheets, the inner dielectric sheet, and the outer dielectric sheet;
removing an exposed end portion of the inner dielectric sheet to form a groove located on an exposed end portion of the inner dielectric sheet; and
connecting first and second lead conductors to the first and second electrode sheets,
wherein the steps of depositing the first electrode layer, depositing the inner dielectric layer, depositing the second electrode layer, and depositing the outer dielectric layer are at an oblique angle to the substrate plane, resulting in additional depositing of the layers along a side of the layers along a side of the protrusion at the angle to the substrate plane, and
wherein the inner dielectric layer is deposited with a first thickness, and wherein the outer dielectric layer is deposited with a second thickness of at least one order of magnitude greater than the first thickness.
2. The method of claim 1 , wherein the steps of depositing the first electrode layer, depositing the inner dielectric layer, depositing the second electrode layer, and depositing the outer dielectric layer are repeated at least once to provide at least two pairs of the first and second electrode sheets, wherein each pair is separated by an outer dielectric sheet.
3. The method of claim 1 , further comprising, in preparation for the planarizing, attaching a mechanically supportive block material adjacent a stack formed by the deposited first electrode layer, inner dielectric layer, second electrode layer, and outer dielectric layer.
4. The method of claim 1 , wherein removing an exposed end portion of the inner dielectric sheet further comprises measuring an electrical, capacitance, or optical measurement between the pair of electrode sheets to indicate when to cease removal.
5. The method of claim 1 , further comprising depositing a dielectric cover layer at an angle or perpendicular to the first and second electrode sheets opposite the substrate to define a gap exposing a portion of the pair of electrode sheets.
6. The method of claim 1 , further comprising roughening an exposed edge of the first and second electrode sheets.
7. The method of claim 1 , wherein each lead conductor diverges in width as the lead conductor extends away from an edge of the electrode sheet.
8. The method of claim 1 , further comprising depositing a gate electrode parallel to the substrate plane and perpendicular to an electrode plane defined by an electrode sheet in the first and second electrode sheets.
9. The method of claim 1 , further comprising forming a channel arranged to introduce a fluid to exposed portions of the first and second electrode sheets.